How Sea Butterflies "Fly" in Water

The video explores the unique movement of Limacina helicina, an Arctic sea butterfly that appears to fly through water using tiny wings. This movement is compared to the flight of hummingbirds and fruit flies, explained through the concept of Reynolds Number in fluid dynamics. The sea butterfly's feeding behavior involves deploying a mucus web to capture plankton, and its buoyancy is affected when disturbed. The video highlights convergent evolution, where sea butterflies and fruit flies have developed similar flight mechanisms despite different environments. It concludes with a promotion for a PBS miniseries showcasing animal behavior filmed by robotic devices.

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